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Activity: Fish Adaptations to the Environment

NGSS Science and Engineering Practices:

NGSS Crosscutting Concepts:

NGSS Disciplinary Core Ideas:


  • Table 4.18
  • Table 4.19
  • colored pencils


A. Brainstorming

  1. Read the description of the ocean habitat assigned to your group in the Habitat Handout below (Table 4.1).
  2. With your group, use class resources, the internet, or the library to research and discuss the special features of your habitat.
  3. Suggest a list of physical features that would help a fish to survive in your group’s assigned habitat.
    • Review Topic 4.3 Structure and Function for detailed coverage of different physical features and forms used by a wide variety of fish species.
    • Recall that there may be multiple “solutions” or physical adaptations that solve the problems of surviving in these habitats.
    • Record your predicted physical features that might help a fish survive in your group’s assigned habitat in the description column of Table 4.19. In the adapted function column, write a brief description of each selected physical feature and include an explanation of how it might function as a helpful adaptation for the fish.

B. Sketch a fish

  1. Use your descriptions in Table 4.19 to sketch a fish that includes all of the adaptations your group predicted to help its survival in this particular habitat.
  2. Submit your completed Table 4.19 and sketch to your teacher.

C. Present ocean habitats and adaptations

  1. Each group will take turns presenting their assigned ocean habitat to the rest of the class. Share the information you researched, and be certain to discuss the difficulties of fish surviving in your habitat.
  2. As each group presents, the other groups should take notes about each habitat. Consider the similarities and dissimilarities between the different ocean habitats.

D. Survival of the fittest

  1. Work in groups to review a fish drawing and Table 4.19 completed for a specific habitat by your classmates.
    1. Evaluate and discuss whether each of the physical features of their fish is an important adaption for survival in the assigned habitat and conditions.
    2. Discuss the challenges fish must endure in order to survive in the assigned habitat.
    3. Discuss the adaptations that might serve as appropriate solutions to address these survival challenges (from your classmates’ completed Table 4.18).
    4. Based on all of the combined physical features of the fish, determine if the fish would (a) thrive, (b) survive, or (c) die. Explain why, and have one group member record the group’s feedback on the worksheet.

Table 4.18. Habitat handout

Habitat Handout
The rocky intertidal is a region of the shore bordered on the seaward side by the reach of ebbing (falling) tides and on the landward side by the reach of flooding (rising) tides. It is essentially the part of the shore that is intermittently awash or exposed as a result of the tide. The boundaries of the intertidal vary with the phase of the moon and with the intensity of wave action, so in practice the region is not defined precisely. The difference between high and low tide in the Hawaiian Islands is generally less than 20 centimeters, but it is meaningful for the distribution of marine organisms on shores where the range is two meters or more. There are fewer species and less diversity on shores where there is a large tidal range, whereas in places with a small tidal range like Hawai‘i, marine plants and animals characteristically arrange themselves to take advantage of conditions of wetness and light. On rocky shores, organisms must be able to retain water and withstand hours of hot sunshine as long as they are wetted occasionally. A tide-pool is small pool of seawater that remains inside rock crevices during periods of low tide.

Corals reefs are shallow ocean habitats found in warm tropical and subtropical waters around the world. Coral reef habitat is formed by living colonies of reef-building cnidarians, called corals. Coral reefs occur in areas with strong wave action as well as in calm lagoons. Although some corals live in deeper water, reef-building corals require bright sunlight in order for the algae that live within their tissue to photosynthesize. Reef-building corals still filter feed—gathering food from the water, but the algae inside their tissues provide additional nutrition, which allows them build hard calcium carbonate reef structures. The reefs that corals build provide shelter for many fishes and invertebrates. Some reef fishes and animals (like the crown of thorns sea star) also feed on coral polyps.

Kelp forests are shallow ocean habitats generated by large algae called kelp. These kelp algae grow vertically from rocky seafloors up to the surface and provide shelter and food for a diverse group of marine organisms. Kelp forests are found exclusively in cool, temperate waters.

The open ocean or epipelagic zone is the area of the world ocean far away from both the seafloor and all shores. This habitat is characterized by patches of microscopic phytoplankton and zooplankton. Fish predators include seabirds and some large jellyfish. Surface waters face intense sunlight and little structural refuge from predators with the exception of floating debris. Open ocean habitats are found around the world from the cold polar regions to the hot tropics.

In the deep water of the ocean, there is massive pressure from the water pushing down from above. The deep sea is also very cold with little or no light. Food is hard to find because the lack of light means that organisms cannot photosynthesize. Thus, there are also fewer organisms in the vast open space. And, there is less habitat structure (no large coral reefs or kelp forests). For these reasons, both food and mates are hard to find.

Arctic (near the North Pole) and Antarctic (near the South Pole) waters are very cold. In fact, in the Southern Ocean Basin, water temperatures range from about -2°C to 10°C. The colder temperatures should be cold enough to freeze the water, but salt in the water keeps it from turning to ice.

Table 4.19. List of fish features

Physical feature or form Description Adapted function
A. Body size and shape    
B. Skin color and scales    
C. Eyes, jaws, and other head features    
D. Mouth and teeth    
E. Caudal fin    

F. Other fins or appendages


G. Behavior



Activity Questions: 
  1. Fish worksheet evaluations
    1. Based on peer comments, which physical features on your fish were effective adaptations?
    2. Which physical features do you think were not effective adaptations for surviving in the assigned habitat?
  2. Do you think your fish could also be well adapted for another habitat? Explain your reasoning.
  3. Was the fish you invented similar to any of the fish your classmates invented for other habitats? Describe the similarities and differences.
  4. What would be likely source(s) of food for your fish?
  5. Using an identification resource, find fish with similar adaptations to the features you described for your fish in Table 4.19. Compare the fish from the identification resource to your drawings. Note adaptation similarities and differences.
Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.